Tag Archives: Aeroacoustics

PhD & MPhil Titles

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If you are interested in coming to UTM as a Ph.D / M/Phil students, and possibly working with me, here are some topics that I’m currently working with;

  1. Bio-inspired airfoil shapes for reduction Leading/Trailing edges noise.
  2. Energy Harvesting for powering IoT Devices using flow induced vibration.
  3. Aerodynamic Performance And Safety For A Proposed Malaysia High Speed
    Train Traveling Under Crosswinds
  4. Aerodynamics loading and Noise emissions from a high speed train
  5. Aeroacoustics refinement of a passenger car DrivAer for NVH improvement

Contact Me at researchsukri@gmail.com

Flow modelling and noise generation of interacting prisms.

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Noise generation is a significant issue for High-Speed Trains (HSTs), and as speeds increase aerodynamically generated noise becomes the dominant noise source. In this article, the effect of nose shape, carriage separation and yaw angle on the aerodynamics and noise generation are analysed using two prisms, representing a HST model. The aerodynamics are modelled using Computation Fluid Dynamics (CFD), and the flow velocity and turbulence intensity in various positions in the wake are compared with experimental hotwire data measured in the Anechoic Wind Tunnel (AWT) at The University of Adelaide, with good agreement. Finally, acoustic beamforming images of the noise generated by the interacting prisms measured in the AWT are presented. The acoustic results show that a blunt nose tends to increase noise at lower frequencies significantly, while increasing prism separation tends to increase noise over most frequencies, but most significantly at midfrequencies, and increasing yaw angle increases noise across all frequencies. Beamforming results show that at lower frequencies, this noise tends to be generated at the leading and trailing edges, while at higher frequencies the noise tends to be generated in the carriage gap.

AIAA Aviation,16-20 June 2014, Atlanta, GA, 20th AIAA/CEAS Aeroacoustics Conference.

Paper: AIAA 2014-3287

Aeroacoustics: an interesting combination between aerodynamics and acoustics

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This morning I was listening a beautiful sound of an aeolian harp from the Youtube. It’s so naturally relaxing and it’s perfect for me to get my mind fresh for the day. This sound was amazingly tuned by the size (diameter) of the string (infinite circular cylinder) and the level of wind speed. In aeroacoustic engineering, they named this airborne noise mechanism as an aeolian tone. It’s actually a dipole type of sound radiation.

Aeolian harp sound radiation is different from the sound radiation from a loudspeaker (monopole) or noise from the engine jet (quadrupole).  The sound sources of aeolian harp consist of two monopole sources of equal strength, but they are in opposite phase. The two sources are located very close to each other when compared to its sound wavelength.

We can control this sound beautifully. Using Lighthill’s acoustic analogy and Curle’s equation for the inclusion the effect of aeolian tone,  we can see how the aeolian tones is controlled by just using a thin flat plate. Please visit my publications if you like to see more.